The overall objective of this project is the synthesis of prostaglandin analogs in which the manifold biological activities of the natural prostaglandins have been separated. This task is essential, since application of prostaglandins in medicine demands that the desired activity be accompanied by a minimum of "side effects". Goals for the current year are: A) Completion of the Synthesis of 10,10-Difluoroprostaglandins. B) Further Studies of the Synthesis of Dithia Analog of the Prostaglandin Endoperoxide. C) Completion of the Synthesis of 8, 12-Seco Prostaglandins. D) Investigation of Alternatives and Modified Routes to 13-Dehydroprostaglandins. E) Investigation of Routes Leading to the Thromboxanes.